Those Odd Numbers on Death Certificates

(As we transition our weekly blog from its old home on Blogspot to its new home on our website, we are revisiting some of our older blog posts so that they can remain in our archive. First published in August 2017, this post has been updated to ensure all links are working and the latest available information is included.)

While working with twentieth-century death certificates, you may have noticed that many have large numbers written on them somewhere in the “cause of death” section. Perhaps you thought these were just random numbers, but it turns out, they are not. Created by the World Health Organization (WHO) in the late 1890s, those numbers are part of the International Code of Diseases or ICD, and they may reveal more information on how your ancestors died, especially if the handwriting and/or the spelling on the certificate is difficult to decipher. Before you plunge in, you may want to read more about the history of the coding system in the FamilySearch Wiki. https://en.wikipedia.org/wiki/International_Classification_of_Diseases.

A detailed account of the ICD system is in an article on the Family History Daily website, but be aware that it is filled with ads.

Older ICD codes are very simple, usually just a few numbers. The current version of the coding system used in the United States is ICD-10-CM (although ICD-11 is in the process of implementation) and it consists of three parts

  1. The first three characters are for the general family of disease or topic.
  2. The next (subcategory/details) adds specifics, like exactly which part of the body or a cause.
  3. The final characters indicate which side of the body or length of illness.

You will find the best source for all ICD historic codes at http://www.wolfbane.com/icd. Be sure to choose the link that corresponds to the revision closest in time prior to the person’s death for the most accurate information.

In the following example, note that the person died in 1912 of “chronic bronchitis with pulmonary abscess.” You can also see the large handwritten number “96” at the bottom of the certificate.

Now, on the ICD website (see link just above the image), we will use the revised code for 1909, the closest date prior to 1912, and we can see that the number 96 stands for asthma, which adds more information to the cause of death.

If it’s been a while since you looked at some of your older death certificates, you may want to take another look to see what more you can learn from those mysterious ICD numbers.